1. Field of the Invention
The invention relates to a portable encrypted storage device with biometric identification, and more particularly to a portable large-capacity storage device with a fingerprint sensor and a method for protecting data stored therein. The invention also correlates to the patent applications to some of the inventors: (a) U.S. patent application Ser. No. 10/998,722, filed on Nov. 30, 2004, and entitled “MEMORY STORAGE DEVICE WITH A FINGERPRINT SENSOR AND METHOD FOR PROTECTING THE DATA THEREIN”; (b) U.S. patent application Ser. No. 10/403,052, filed on Apr. 1, 2003, entitled “CAPACITIVE FINGERPRINT SENSOR,” and published on Oct. 9, 2003 as US20030190061A1; (c) U.S. patent application Ser. No. 10/434,833, filed on May 13, 2003, entitled “PRESSURE TYPE FINGERPRINT SENSOR FABRICATION METHOD,” and published on Nov. 20, 2003 as 20030215976A1; (d) U.S. patent application Ser. No. 10/414,214, filed on Apr. 16, 2003, and entitled “THERMOELECTRIC SENSOR FOR FINGERPRINT THERMAL IMAGING”; (e) U.S. patent application Ser. No. 10/638,371, filed on Aug. 12, 2003, and entitled “CAPACITIVE MICRO PRESSURE SENSING MEMBER AND FINGERPRINT SENSOR USING THE SAME”; and (f) Taiwan Patent Application No. 090112023, filed on May 17, 2001 , and entitled “CAPACITIVE PRESSURE MICROSENSOR AND METHOD FOR MANUFACTURING THE SAME AND DETECTING SIGNALS OF THE SAME”, now issued as Invention Patent Number 182652.
2. Description of the Related Art
The conventional method for protecting the personal data is often made by way of password protection. However, using the password to protect the personal data is troublesome because the user tends to forget the password and the password may also be dangerously cracked. Hence, the biometrics identification methods based on the biometrics data particular to the personal, such as the fingerprint, voice, signature, and iris, have been gradually developed in order to provide the more complete and effective data protection methods. The advantages are that the biometric feature is always kept on the user and the user does not need to memorize the feature, the biometric feature cannot be stolen, and the fingerprint biometrics feature protection method is strict and very convenient.
Recently, owing to the invention of the chip-type fingerprint sensor, the miniaturized electrical product incorporated with the fingerprint identification device becomes the technology that can be implemented. The associated technology can be found in the above-mentioned (b) to (f) patents. Thus, novel personal applications, such as the portable electrical products with the fingerprint identification function, have been developed.
More particularly, the aspect of the storage medium protection is an important development item incorporated with the biometrics identification method. For example, U.S. Pat. No. 4,582,985 issued on Apr. 15, 1986 has disclosed a method for protecting data in a memory by way of fingerprint identification, wherein the fingerprint is captured and identified in the same independent device. Although the application object thereof is to prevent the personal credit card from being counterfeited, this device has a high price because the image processing and identification module needs a high-level microprocessor, such as a 32-bit RISC (Reduced Instruction Set Computer, RISC) processor or DSP (Digital Signal Processor) chip, in addition to that the fingerprint sensor is needed, which causes the independent identification device not easy to be popularized.
U.S. Pat. No. 6,213,403; WO 02/42887 A2; U.S. Pat. No. 6,213,403; EP 124079A1; U.S. Pat. Publication No. 2003/005337; and GB 2387933 disclose devices for protecting data stored in the memory by way of fingerprint identification. Each of the devices is similar to the storage device having a fingerprint sensor, as disclosed in U.S. Pat. No. 4,582,985, and the disclosed fingerprint identification architecture is mainly the independent fingerprint identification device, in which the fingerprint is captured and identified in the same device.
Heretofore, the prior arts have a common feature of providing an independent fingerprint identification device including a fingerprint sensor, and a fingerprint image processing and identification IC. Such a design is intuitive and easily implemented and there is no need to install the fingerprint application program in the terminal system and the convenience of plug-and-play function may be provided. However, the prior art devices have an important problem of the high prices because a fingerprint image processing and identification IC and its associated memory components have to be utilized. Usually, the IC is the 32-bit RISC or DSP so as to perform the fingerprint identification effectively. Consequently, the conventional portable storage device with a fingerprint sensor has the drawback of high cost.
In order to solve the high cost problem, it is preferred to utilize the microprocessor of the terminal host to execute the fingerprint image processing and identification so as to effectively reduce the cost. For example, as disclosed in U.S. Patent Publication No. 2003/005337, the fingerprint processing and identification software can be installed in the terminal host in advance, and the microprocessor of the terminal host can execute the fingerprint image processing and identification processes. However, such a design has a greatest drawback that the user cannot conveniently use the device over various terminal hosts in a plug-and-play manner, or the user has to spend time to install the software laboriously.
Therefore, the above-mentioned (a) patent discloses a method for solving the above-mentioned problems, in which a fingerprint application program with the function of the fingerprint image processing and identification is automatically run in the terminal host without the fingerprint processing and identification software being installed in the terminal host in advance. In this patent, the microprocessor of the terminal host is used to execute the fingerprint image processing and identification process, and the device can be conveniently used and the cost thereof can be effectively reduced.
Heretofore, the prior arts protect the data in the memory, especially a non-volatile flash memory, according to human fingerprints. However, other types of portable large-capacity storage units, especially the magnetic hard disk and optical disk, have become another important development trend under the considerations of the cost and the high capacity.
U.S. Patent Publication No. 2001/0023375 discloses a fingerprint hard disk device, in which the authority for accessing the data in the magnetic hard disk is determined by way of fingerprint identification. The '375 patent mainly utilizes an independent fingerprint identification module for capturing, storing and comparing the fingerprints. After the identification of the user is determined, a control signal is provided to an electric controlled switch so as to disable or enable the hard disk. This design is advantageous because no fingerprint application program has to be installed in the terminal host and the plug-and-play function can be conveniently provided. However, this product has a high price. Furthermore, using the hardware switch to control the enabled/disabled state of the hard disk is not a safe design and tends to be easily cracked because a hacker can easily provide a fake signal to the hardware switch to replace the fingerprint authentication. Meanwhile, the method for protecting the data stored in the hard disk is not clearly described in this patent.